Q: A jeweler has a diamond containing 1.20 g of pure carbon. How many moles of carbon are present in the diamond? (Molar mass of carbon = $12.01\ \mathrm{g/mol}$)

$1.20\ \mathrm{g} \times \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}} = 0.100\ \mathrm{mol}$

Q: A sample contains $4.8 \times 10^{-2}$ moles of carbon. What is the mass of carbon in the sample? (Molar mass of carbon = $12.01\ \mathrm{g/mol}$)

$4.8 \times 10^{-2}\ \mathrm{mol} \times 12.01\ \mathrm{g/mol} = 0.58\ \mathrm{g}$

Q: If you have 24.02 g of carbon, how many moles of carbon do you have?

$24.02\ \mathrm{g} \times \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}} = 2.00\ \mathrm{mol}$

Q: A chemist needs $0.25\ \mathrm{mol}$ of carbon for an experiment. What mass of carbon should they weigh out? (Molar mass of carbon = $12.01\ \mathrm{g/mol}$)

$0.25\ \mathrm{mol} \times 12.01\ \mathrm{g/mol} = 3.00\ \mathrm{g}$

Q: Which equation would you use to convert 0.58 g of carbon to moles?

$0.58\ \mathrm{g} \times \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}}$

Q: A diamond contains $1.5 \times 10^{-1}$ moles of carbon. What is the mass of carbon in the diamond?

$1.5 \times 10^{-1}\ \mathrm{mol} \times 12.01\ \mathrm{g/mol} = 1.80\ \mathrm{g}$

Q: Which of the following statements about the mole concept is correct?

A mole is the amount of substance that contains $6.02 \times 10^{23}$ particles.

Q: A student measures out 6.005 g of carbon. How many moles of carbon does this represent?

$6.005\ \mathrm{g} \times \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}} = 0.500\ \mathrm{mol}$

Q: A medical device uses 0.75 g of carbon. How many moles of carbon are used? (Molar mass of carbon = $12.01\ \mathrm{g/mol}$)

$0.75\ \mathrm{g} \times \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}} = 0.062\ \mathrm{mol}$

Question 1

A jeweler has a diamond containing 1.20 g of pure carbon. How many moles of carbon are present in the diamond? (Molar mass of carbon = $12.01\ \mathrm{g/mol}$)

Accepted Answer

$1.20\ \mathrm{g} 	imes \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}} = 0.100\ \mathrm{mol}$

Question 2

Which of the following correctly describes the process for converting grams of an element to moles?

Accepted Answer

Divide the mass in grams by the molar mass of the element.

Question 3

A sample contains $4.8 	imes 10^{-2}$ moles of carbon. What is the mass of carbon in the sample? (Molar mass of carbon = $12.01\ \mathrm{g/mol}$)

Accepted Answer

$4.8 	imes 10^{-2}\ \mathrm{mol} 	imes 12.01\ \mathrm{g/mol} = 0.58\ \mathrm{g}$

Question 4

If you have 24.02 g of carbon, how many moles of carbon do you have?

Accepted Answer

$24.02\ \mathrm{g} 	imes \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}} = 2.00\ \mathrm{mol}$

Question 5

A chemist needs $0.25\ \mathrm{mol}$ of carbon for an experiment. What mass of carbon should they weigh out? (Molar mass of carbon = $12.01\ \mathrm{g/mol}$)

Accepted Answer

$0.25\ \mathrm{mol} 	imes 12.01\ \mathrm{g/mol} = 3.00\ \mathrm{g}$

Question 6

Which equation would you use to convert 0.58 g of carbon to moles?

Accepted Answer

$0.58\ \mathrm{g} 	imes \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}}$

Question 7

A diamond contains $1.5 	imes 10^{-1}$ moles of carbon. What is the mass of carbon in the diamond?

Accepted Answer

$1.5 	imes 10^{-1}\ \mathrm{mol} 	imes 12.01\ \mathrm{g/mol} = 1.80\ \mathrm{g}$

Question 8

Which of the following statements about the mole concept is correct?

Accepted Answer

A mole is the amount of substance that contains $6.02 	imes 10^{23}$ particles.

Question 9

A student measures out 6.005 g of carbon. How many moles of carbon does this represent?

Accepted Answer

$6.005\ \mathrm{g} 	imes \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}} = 0.500\ \mathrm{mol}$

Question 10

A medical device uses 0.75 g of carbon. How many moles of carbon are used? (Molar mass of carbon = $12.01\ \mathrm{g/mol}$)

Accepted Answer

$0.75\ \mathrm{g} 	imes \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}} = 0.062\ \mathrm{mol}$

Question 11

Which of the following is the correct setup to find the number of moles in 10.0 g of carbon?

Accepted Answer

$10.0\ \mathrm{g} 	imes \frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}}$

Question 12

A scientist wants to prepare $2.5 	imes 10^{-2}$ moles of carbon for a reaction. What mass of carbon should be used?

Accepted Answer

$2.5 	imes 10^{-2}\ \mathrm{mol} 	imes 12.01\ \mathrm{g/mol} = 0.30\ \mathrm{g}$

Question 13

Which of the following is NOT a correct use of the molar mass of carbon?

Accepted Answer

To convert atoms of carbon directly to grams without using Avogadro's number.

Question 14

A forensic scientist finds a sample containing $3.00 	imes 10^{-2}$ moles of carbon. What is the mass of carbon in the sample?

Accepted Answer

$3.00 	imes 10^{-2}\ \mathrm{mol} 	imes 12.01\ \mathrm{g/mol} = 0.36\ \mathrm{g}$

Question 15

A student incorrectly calculates the number of moles in 0.58 g of carbon by multiplying by the molar mass. What value do they get?

Accepted Answer

$0.58\ \mathrm{g} 	imes 12.01\ \mathrm{mol/g} = 6.97\ \mathrm{mol}$

Question 16

Which of the following best explains why the conversion factor $\frac{1\ \mathrm{mol}}{12.01\ \mathrm{g}}$ is used to convert grams of carbon to moles?

Accepted Answer

Because $12.01\ \mathrm{g}$ is the mass of one mole of carbon atoms.

Converting Between Grams and Moles: Carbon Example

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